Self-releasing vehicle bumper



n 1940- A. .c. DE HOFFMANN 2,205,592

SlLF-RELBASING VEHICLE BUMPER Filed Sept. 2, 1957 2 Sheets-Sheet 1 d C. def/ofi'mann. fllexan er INVENTOR.

' ATTORNEYS.

J1me 1940- A. c. DE HOFFMANN I 2,205,592

saLr-amms'me VEHICLE BUIIPER 2 Sheets-Sheet 2 Alexander Cf aeHof/marzrz. INVENTOR.

Patented June 25, 1940 I UNITED STATES PATENT OFFICE SELF-RELEASING VEHICLE BUMPER Alexander 0. de Hofimann, New York, N. Y. Application September 2, 1937, Serial No. 162,096

4 Claims. (01. 29355) This invention relates to improvements in bumper equipped with a further modified form automobile bumpers and more particularly to a of bumper releasing attachment. self-releasing bumper which is automatically Figure 2 is an end elevation of the structure disengageable from entanglement with the shown in Figure 1.

bumper of another vehicle, by reason of the mo- Figure 3 is a detail perspective View of one of tive power of the automobile on which the selfthe bumper releasing members. v releasing bumper is mounted. Figure 4 is a horizontal sectional view on the It is a common occurrence for two bumpers of line 44 of Figure 3. automobiles to become entangled by contact Figure 5 is an enlarged sectional side elevawith each other due to trafiic congestion or tional. view illustrating the circle principle on 10 crowded parking conditions or by careless drivwhich the. bumper releasing member is coning. When such entanglement of bumpers ocstructed. curs, it results in loss of time in effecting a dis- Figures 6 to 9 inclusive are detail sectional engagement of the bumpers, traflic tie-up on side elevational views of the various positions of T5 congested streets and highways, and very often a pair of bumpers during their period of movethe entangled bumpers become damaged by ment from entangled to disentangled position. breakage which entails expense to the automobile Figure 10 is a sectional perspective view of a owners for repair or replacement of the damcombined bumper ba a guard ucted. 11 aged parts. It is therefore the primary object the e releasing principle 9 of this invention to provide an automobile bump- My invention about to be described is based 2 er which is self-releasable under the motive upon a circle principle of curved cam surfaces power of the automobile on which it is mounted and by referring to Figure 5, the clover-leaf which eliminates the above mentioned difliculties shape b mper u r attachment 31 is constructed which arise by use of the automobile bumpers on the principle of four separate circles. Start- 9' of the present conventional construction and ing with the main circle d which is of a diameter design. equal to the height of the clover-leaf shape at- Another feature of the invention is the protachmehi? member there iS Shown pp d, Vision of an improved automobile bumper which lowe i les f n y of l k i meter whose axes may be safely released from locked entangleare in vertical alinement with the axis of the g ment with the bumper of another automobile by lower Circle and a rear Circle h Whose axis is reason of th circle cam principle on which th on the same horizontal plane as the main circle improved bumper is constructed. 01. Whereas, the circle h is of the same diameter Another feature of the invention resides in a as the circles 1 ends, the relative size between self-releasable automobile bumper which rides these circles m y be v r to ch e de r e free of any entanglement with another bumper 0f the Cam surfacfis 0f h attachment e ber by the direct pull exerted'thereon when the auto- 37 for reasons hereinafter e p edmobile is placed in motion under its own motive The bumper attachment s med of a power. single piece of rigid material and includes a A still further feature of the invention is to fr nt v al impact portion 38 which ybe 5' provide an automobile bumper having the above v d as shown in the drawings, f at, an 40 features which may be applied to automobiles upp r e rw r ly x ndin m surface 39, the now in use, as well as newly manufactured cars, external curvature of which is an arc of the and which is simple and inexpensive of co nstrucircl 1, a r w y extending central m p rtion, and attractive in appearance so as n t t tion 40, the external'curvature is an arc of the detract from the artistic designs of the modern circle 72, and a lower rearwardly extending cam automobile. surface 4|, the external curvature of which-is With thes and other bje t in i th an arc of the circle g. Also formed on the arcs vention resides in the certain novel construc- 0f the circles fand g a p and bottom rtion, combination and arrangement of parts, the wardly extending 0am ip p o s 42 and '43 essential features of which are hereinafter fully esp ve y, either o Which is adapted to gmdll- 50 described in the following specification, are parally ease an entangled bu p t0 fi a disenticularly pointed out in the appended claims, ga e W a b p On w h e attachand are illustrated in the accompanying drawment 31 is mounted. I ings, in which: f By utilizing the segments of the circles g, Figure 1 is a top plan view of an automobile and h in determining the curvature of the cam 55 surfaces, there is provided crotches 4 and 55 between the cam surfaces 39 and 46, and between the cam surfaces 40 and 4| respectively, which act as rest shoulders when the attachment 3'! is moving over or under an entangled bumper.

In Figure 5 of the drawings, I have illustrated the length by degrees of the upper half (180 degrees) of the main circle d of the various segmental cam surfaces, but the length and curvature of such cam surfaces maybe increased or decreased and curved on arcs of circles proportionately different than that herein illustrated.

The bumper attachment 3"! is of clover-leaf shape in side elevation and is provided with an opening it through which the bumper bar 4'1 extends. The outer side of the bumper bar 41 fits against the forward side wall of the opening 46 or what is shown in the drawings as the rear side of the vertical impact portion 38. Bolts 48 pass through the portion 38 and bumper bar to rigidly fasten these parts together. Two attachment members 31 are mounted on the bumper bar 4'5 as illustrated in Figure l of the drawings.

In Figures 6 to 9 of the drawings, I have illustrated the rear of an automobile X and the front of an automobile Y equipped with attachment members 3'1. In Figure 6 the bumper bars of the automobile X and Yale entangled with the bar 3'! of the automobile X disposed behind and overlapping the plane of the bar 4'! of the automobile Y. Whereas, both bars ii are equipped with the attachments 31 and in such case the attachments 31 on both bumper bars coact in effecting disengagement of the entangled bumpers, but the attachments 3'! on either of the bumper bars are sufficient to effect disentanglement and for illustration purposes, assume that only the bumper bar l'i of the automobile Y is so equipped. To eflect disengagement either or both automobiles may be placed in motion away from each other, whereupon the bumper bar ll of the automobile X is forced upwardly by its engagement with the upper portion of the curved cam surface 40, of the attachments 3i on the lower bumper bar 4'! of the automobile Y. The upper bumper bar 4'! comes to rest within the crotch or shoulder id and the hurdling operation of the bumper bar is momentarily stopped as seen in Figure '7. Continued relative movement of the automobiles, X and Y, causes the cam surface 39 to further force the upper bumper bar 41 upwardly as shown in Figure 8 which position illustrates the upper bumper bar it? about to be freed. Further relative movement between the automobiles X and Y permits the upper bumper bar 4'! to gradually ride down the forwardly and downwardly curved cam portions or lips 42, as shown in Figure 9, whereupon the bumpers M of the automobiles X and Y are completely disentangled. Should the bumper bar 41 of the automobile X be entangled beneath the bumper bar 41 of the automobile Y, the bar 4'! of the automobile X will pass over the cam surfaces on the lower half of the attachment members 37 with the same hurdling result of the bumper bars relative to each other.

By reason of the spring suspension of the bodies of the automobiles X and Y, there is a relative yielding movement of the bodies of the automobiles during the riding of the entangled bumper bars over and under each other, thus the wheels of the automobiles remain in tractive engagement with the road.

The outer cam surfaces are round so that there is minimum contacting surfaces between the attachment members and a bumper bar to be disentangled. However, such contacting surfaces on the attachment members may be flat or pointed if desired. Also, while I have illustrated the body of the attaching member as being solid, the same may be made hollow for lightness if desired.

In Figure of the drawings, the principle of the clover leaf shape attachment member 3'! is embodied in a bumper bar 49 and is provided with a front impact portion 38', and rounded cam surfaces 39', 40', 4|, 42, and 43, which are the equivalent in construction and function as the surfaces 39, 40, 4i and 42 of the attachment member 31. To assure positive bumper protection and disentanglement of locked bumpers under any and all conditions, the bumper bar d9 may also be equipped with attachment members 31.

In view of the varying weights of automobiles and motive power thereof, the rounded cam surfaces on the bumper bar attachment members may be varied proportionately in order to function on minimum power sufficient to effect a disentanglement of a pair of entangled bumper bars, In other words, it should not be necessary for an operator of an automobile to speed up the engine to the maximum to produce a pulling force great enough to cause the bumper attachment to efficiently operate regardless of the weight and horse power of the engine.

While I have shown and described what I con sider to be the best embodiments of my invention, I wish it to be understood that such changes and alterations as come within the scope of the appended claims may be resorted to if desired.

Having thus described the invention, what I claim as new and desire to secure by Letters Patent of the United States, is:

1. A disentanglement attachment for motor vehicle bumpers comprising in combination with a bumper bar, an attachment member fixed to said bumper bar and including a body of substantially clover leaf shape in side elevation having round end surfaces and an intermediate round surface, and rest shoulders at the juncture of the intermediate round surface with the round end surfaces substantially as and for the purpose specified.

2. A disentanglement attachment for motor vehiclt bumpers comprising a rigid body provided with acentral rearwardly projecting curved cam surface, and upper and lower forwardly and rearwardly extending curved cam surfaces contiguous with said central cam surface, all of said cam surfaces being curved on the arcs of circles of different axes, the meeting ends of the curved cam surfaces defining rest shoulders for engagement by an entangled bumper when being cammed over said cammed surfaces.

3. A disentanglement attachment for motor vehicle bumpers comprising a rigid body having a vertical front wall, said body being formed with a central rearwardly projecting curved cam surface, and upper and lower forwardly and rearwardly extending curved cam surfaces contiguous with said central cam surface, the meeting ends of the curved cam surfaces defining rest shoulders all of said cam surfaces being curved on the arcs of circles of difierent axes, the forwardly extending portions of the upper and lower cam portions being slightly disposed beyond the plane of said front wall.

4. A bumper guard comprising a one-piece body having a bumper bar opening extending transversely therethrough, forwardly and rearwardly extending convex cam surfaces at the top and bottom of said body, an intermediate 7 convex cam surface at the rear of said body meeting the rear ends of the top and bottom cam surfaces, the meeting ends of said intermediate cam surface with the top and bottom cam surfaces defining upper and lower shoulder rests for an entangled bumper when being cammed forwardly over the cam surfaces.

ALEXANDER c. DE HOFFMANN. 

